Microbiology

How Swine Flu Viruses Mutate



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The ability to mutate is a prerequisite for most bacteria and viruses if they were to adapt to the ever-changing living environments and challenges. Swine flu is no different and its mutational ability made it possible for the virus to transit from infecting pigs to infecting humans. Thus, being able to mutate from one host to another or from one species to another has given influenza viruses such as swine flu its long life and the ability to resist eradication attempts through various means including through vaccination.

How do viruses reproduce?

In order to reproduce, a virus has to rely on its host cell following its attachment to the same through membrane bound proteins. Following attaching to the host cell membrane, the virus would inject its genetic material into the host cells where reproduction of the generic material (RNA and DNA) take place according to the genetic instructions given by the virus DNA/RNA sequences. The reproduced viruses would then leave the host cell in order to infect other cells in the body.

Why do viruses need to mutate?

With time, the host organism or the animal would produce immune markers to recognize the invading virus and therefore kill the virus or prevent it from being attached to the host cells, as it tries to reproduce. Therefore, unless the virus can mutate and change its genetic constituency to be recognized by the immune systems as a different organism or a particle, it may not be able to sustain for much longer. Thus, being able to mutate is one of the key features of a successful microorganism including the swine flu virus.

How does the swine flu virus mutate?

When it comes to DNA viruses and RNA viruses, the ability to mutate is different between the two. The probability of a DNA virus developing a mutation would be rather low and therefore such viruses stay the same when it comes to its genetic constituency over many years. The reason for low levels of mutations in DNA viruses is that DNA replication makes use of proof reading mechanisms, which make sure that there are no errors before reproducing the genetic material. However, with regard to RNA viruses, there are no such proof reading mechanisms adapted during replication of the genetic material and therefore are much prone to develop errors or ‘mutations’ at the end. Thus, RNA viruses such as ‘swine flu’ and ‘HIV’, mutate at a rapid pace when considering its DNA virus counterparts such as ‘small pox’.

Secondly, when the same host becomes infected with different strains of viruses such as that of swine flu and influenza, it is possible for new strains to emerge with a combination of genetic material from different strains. For example, pigs have receptors for all three strains of influenza and therefore could act as an incubator to produce a mix version of the influenza viruses.

Environment seems to be playing a vital role in the rate of mutation as well. Thus, with regard to swine flu, a densely packed pig farm would be a source for mutant forms of the virus as the viruses can quickly move from one host to another within a short period of time.

What are the chances of a pandemic ‘swine flu’ in the future?

According to experts, it is unlikely that another H1N1 like event will take place in the near future because most Americans have grown immune to most strains of pandemic influenza viruses. At the same time, mass vaccinations have made the virus susceptibility extremely low although it cannot be considered eradicated at any length. However, the risk of a major mutation is always present with RNA viruses such as swine flu and if it occurs, the likelihood of a pandemic event could not be dismissed.

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More about this author: Dr Pandula Siribaddana

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ARTICLE SOURCES AND CITATIONS
  • InfoBoxCallToAction ActionArrowhttp://www.cbc.ca/news/technology/story/2009/04/27/virus-mutate.html
  • InfoBoxCallToAction ActionArrowhttp://www.telegraph.co.uk/health/swine-flu/5828423/Has-swine-flu-started-to-mutate.html
  • InfoBoxCallToAction ActionArrowhttp://www.webmd.com/cold-and-flu/news/20100930/experts-new-h1n1-swine-flu-pandemic-unlikely